That's cool; of course I love to learn, too. And I love to speculate and theorise at times!

Also I am aware that whilst that is mentally fun, it can distract us at times, enough to lose our way. Not preaching here - but I have noticed over years reading others' posts, that for some it can become an excuse never to start the journey.

811 makes sense, and is thoroughly scientifically and practically proven. That's enough for me, and many others. The more successful a system is, the more bashing it will get from envious competitors, which can cast doubts even in those having success.

I doubt there is any ultimate way to count calories; the body likely burns very slightly differently from day to day, even doing the same activites. I still feel the best guide is the simple formula in the original book.